Moisture Sensor

Moisture sensor comes in variety of shapes, however the principle is the same. In hackSpace we have two different types of moisture sensor they are measuring the moisture in soil and similar materials. The two large exposed pads function as probes for the sensor, together acting as a variable resistor. The more water that is in the soil means the better the conductivity between the pads will be and will result in a lower resistance, and a higher SIG out. The other sensor on the left measures the conductivity between the small copper tracks on the PCB. This sensor also can be used to measure moisture in the soil, however it will be more sensitive then the one on the right.

To get the Moisture Sensor working all you will need is to connect the VCC, GND and an S pins to your Arduino. The project on your right will be showing the values in the serial monitor but also the LED will turn ‘ON’ depending on the amount of water in the soil. One commonly known issue with soil moisture sensors is their short lifetime when exposed to a moist environment. To combat this issue the PCB coated in Gold Finishing (Electroless Nickel Immersion Gold), which protects the PCB from the moisture.